I used to think this, but then I read the essay, “War is a racket” which (iirc) was written pre-military-industrial-complex. It seems we’ve always been pretty dishonest about most of our aggressive actions.
The Spanish-American War was likewise begun under suspicious circumstances, but it was the first fueled mainly by the press.
The US also engaged in pointless wars like WWI and unjust wars like the Indian Wars following the Civil War.
"War is a racket" sounds interesting, so I'd be curious to read the arguments. Maybe my interpretation is wrong or incomplete! I do think there was a significant shift from wars being perpetrated by elected officials seeking political ends to wars being largely planned and executed by the MID (and the press), with the elected leaders dragged along like the tail wagging a dog.